Compression gauge



June ll, 1929.

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COMPRESSION GAUGE Filed Feb. 24, 1923 Patented June l1, 19.2S.

UNITED STATES y vv1,716,399 l 4PATENT OFFICE.

ALEX WATTEBS, 0F CHICAGO, IIIJCINOLE.`

COMPRESSION GAUGE.

Application filed February 24, 1923. Serial No. 620,861.

Y This'. invention relates more particularly to devices for testing the 'compression internal combustion engines although it may of course be used for testing pressures wherever it may be applicable; y

The objects of this invention are to provlde a simple and eflicient gauge for testing englues; to provide a gauge of lthis character which will be suiliciently light so that it may be readily carried in the pocket; to provide a gauge which is adapted to be used with dify ferent sized outlets or spark plug-openings and also with other outlets or valves; and 1n general to provide such an improved gauge as will be described more fully hereinafter.

Inthe accompanying drawings illustrating this invention:

Figure 1 is a side view showing the indicating member in partly raised position;

gigure 2 is a longitudinal sectional view; an

Figure 3 is an end view. A

In these drawings the device is shown on an v enlarged scale as compared with the common 4 which is threaded at its lower end for encommercial forms.

The particular formof thedevice shown in thesedrawings has a base or coupling portion gagement with the usual threaded opening provided in an engine for the spark plu As different engines have different threads for different plugs, I prefer to provide the connector with a plurality of such threaded por--A This base or connector is also preferably provide-d with a knurled portion 7 for Couven-- ience in turning the same either by hand or with a suitable wrench or tool. A cylindrical body portion or tube 8 fits in the connector 4 and is held in position by being fgrced therein or in any other suitable manneri A plate or washer 9 lits over the open end of the cylinder 8 and has a .projection 10 for' engagement with the stems of certain valves when the de# vice is to be used in connection therewith.' This washer has an inlet hole 1 1 for admit-l tingair into the cylinder.v A rubber washer or 'gasket 12 is placed vbetween the washer 1 1 andthe apertured end 13 of the connector 4, this end being in the nature of an annular flange against which the washer may be pressed when the parts are assembled.

as t

` position by a cap 17 'which' has an inwardly extending lia-nge 18.

A slidablc and adjustable indicating member coacts with the spring piston or plunger for indicating and registering the pressure. This device preferably comprises a rod 19 having an indicating scale or scales 20 there- 70 on. The lower. end of this rod is threaded as shown at 21 for receiving an adjusting screw 22 which engages with the upper portion of the piston 14.v This screw is preferably providedwith a lock'nut 23 for locking it in ad- 75 justed position.' A spring ring 24 is inserted between the liange 18 and the washer 16 and engages the rod' or indicating member 19 so that it may be held in adusted position after it has been acted upon y the piston. The Aa0 rod or indicating member 19 is also provided with a head or cap 2,5 for pressingit back into the tube or for wlthdrawing it therefrom. j

When the device is to be used -for testing 'an engine, the spark p lug is removed and the 85 gauge is screwed into position in the place of the plu g. The'engine is then turned over and e air or gases are compressed in the engine cylinder they will pass through the openingll into the tube or cylinder 8 and raise the 90 piston .against the compression of the spring.YV 15 which ispropersly calibrated for registering such pressures. The movement ofthe piston projects the indicating member 19 outwardly and the pressure is indicated by the scale or scales thereon. The indicating member 1s held in its outermost position bythe spring ring 24 so that the extreme pressure. will be be indicated. When the pressure is reduced, the piston 14 will'return to normal position, 100 leavingzthe indicating member in its projected position until it is again pressed inwardly b lthe operator. It is welllmown-that it isditlisi cult to make compression springs suiiiciently` accurate so that they are uniform and the '105 tension on the 'spring may also change after it has been used. For this reason the adjusting screw 22 which adjusts the indicating member with respect to the piston is an extremely desirable feature in connection with such auges. A

It will be noted that the details of construction may be modified in order to rovide a gauge fordijerent purposes or di erent engines and therefore I do not wish to be limited to the exact arrangement shown, except as specified in the following claims', in whichI claim:

1. A compreion gauge comprising a cylinder, having 'an inlet aperture at one end, a piston' in sai cylnder,'a compression spring engaging with said piston, an abutment at the opposite end'of` the cylinder for engagement with the spring, an indicating rod coacting with said iston but disconnected therefrom and exten ing out throu h the end of the cylinder and means for ad]usting the rod wlth respect to the piston to vary the position of the indicating marks on said rod with respect to p the piston when the rod is in contact with the pist@ l 2. A gauge of the character set forth, comprising a cylindrical body portion, a connector l at one end of the body portion, a piston in said cylinder, a compression spring engaging with said piston, an abutment at the opposite end of the cylinder for engagement with the spring, a cylindrical indicating rod coacting with said piston and extending out through the end of the cylindergthe end of said rod being adapted to engage with the piston but not connected thereto, means for adjusting the rod with respect to the piston to adjust the scale on said rod withrespect to the'piston when the rod and piston are in operatlve pressure indicating with the washer, a connecting member fit-v ing position and means for holding the rod 'i in position for indicating the movement of the piston.

3. A compression gauge comprisingpa cylinder having an apertured washer with a central projection at one end thereof, a gasket engagting over the cylinder and having an inwardly extending flange engaging .with the gasket and adapted to hold the gasket and washer in position, said lconnecting member having threads on the outer surface thereof, a washer fitting over the opposite end of the cylinder, a

'cap engaging with the cylinder for holding said last named washer, a spring ring interposed between the washer and cap, a piston mounted 1n said cylinder, a compression washer and an indicating member engaging with the spring ring and adapted to be moved in one direction only by said'piston.

4.. In a pressure gauge, the combination of a cylinder, a piston in said cylinder, an indicating member adapted to be moved outwardly only by said piston, means for holdingthe indicatin member in the position to which it is actuated by the piston, and means interposed between the indicating member and the piston for adjustin the distance Vbetween the piston and the in icating member, when said member is in operative`engagement with the piston.

ALEX- WATTERS. 

